There are currently
hundreds of thousands of acres of relatively young, densely
stocked Douglas-fir (Pseudotsuga menziesii) forests in
western Oregon. Thinning, a process that reduces the density
of trees, is planned or being considered for a significant portion
of this acreage. Thinning is increasingly used in young forest
stands to meet a diversity of objectives. It is often used to
reduce competition among trees, thereby increasing growth rate
and reducing competition-induced mortality of the remaining
trees. Recently, thinning has been identified as a potential
approach to enhance wildlife habitat
and to accelerate the development of characteristics typical
of older forest stands, including presence of large-diameter
trees, snags, and logs, a well-developed understory, and multiple
levels of the canopy.
In the Northwest Forest Plan, thinning has been identified
as an acceptable silvicultural practice in stands less than
80 years old in Late Successional Reserves west of the Cascades.
Thinning dramatically influences many aspects of stand structure,
and consequently could strongly influence presence and abundance
of wildlife. Despite this, there is a limited amount of data
documenting the implications of 
commercial thinning to wildlife populations, and most of those
data are the result of observational studies. The purpose
of this study is to examine the influence of commercial thinning
on bird populations by examining bird abundance in control
(unthinned), moderately thinned or heavily thinned sites.
For additional information about this research study see the
2001 CFER
Annual Report. (1.1 MB)
